Application of statistical experimental design to the treatment of bleaching kraft mill effluent using a mediated free radical system

The aim of this work was to evaluate the effect of chelator mediated-Fenton reaction (CMFR) on the chemical oxygen demand (COD) removal from bleaching kraft mill effluent. Effluent treatments were carried out to study the effect of the chelator 3, 4-dihydroxyphenylacetic acid (DOPAC), Fe3+ and H2O2 concentrations on COD removal. For optimization of COD removal, the methodology of statistical experimental design was employed. The estimated second-order polynomial multiple regression model predicts a maximum COD removal of 75.5% (COD/COD0 = 0.245) at the confidence level of 95%. Analysis of variance (ANOVA) showed a good coefficient of determination (R2) value of 0.90, thus ensuring a satisfactory adjustment of the second-order regression model with the experimental data. Indeed, CMFR proved to be a potential process to treat industrial effluents characterized by its high COD.